Diabetes mellitus is a serious metabolic disease which affects more than 100 million people worldwide. In the USA there are more than 12 million diabetics with 600,000 new cases diagnosed every year. The prevalence of diabetes mellitus is increasing, which means in particular a high frequency of complications as well, leading to a substantial impairment of quality of life and life expectancy. Because of diabetes-associated microvascular complications, in the industrialised countries type 2 diabetes is currently the most common cause of adult-onset loss of vision, renal insufficiency and amputations. In addition, type 2 diabetes is associated with a two-to five-fold increase in the risk of cardiovascular disease.
The UKPDS study (United Kingdom Prospective Diabetes Study) showed that intensive treatment with common therapeutic agents, e.g. metformin, sulphonylureas or insulin, results in only a limited improvement in glycaemic control (difference in the HbA1c value ˜0.9%). Moreover, glycaemic control deteriorated considerably over time even in patients in the intensive treatment group, and this was put down to a deterioration in beta cell function. Diabetes is also a major cause of damage to the retina at the back of the eye and increases the risk of cataract and glaucoma. Finally, diabetes is associated with nerve damage, particularly in the legs and feet, which affects the patient's ability to feel pain and contributes to serious infections. All in all, complications of diabetes are one of the major causes of death worldwide.
Adiposity (obesity) is the result of an imbalance between calorie intake and energy consumption. It correlates to a high degree with insulin resistance and diabetes. However, the molecular mechanisms that are involved in obesity/diabetes syndromes are not yet clear. At an early stage of the development of obesity, an increased insulin secretion balances out the insulin resistance and protects the patient from hyperglycaemia. However, after a time, the beta cell function worsens and non-insulin-dependent diabetes develops in about 20% of the obese population. Obesity has thus become a critical risk factor for diabetes, but the factors that predispose one group of patients to a pathological change in insulin secretion as a response to the accumulation of fat are currently unknown. Obesity also significantly increases the risk of the development of cardiovascular disease. Diabetes is also implicated in the formation of kidney complaints, eye complaints and problems of the nervous system. Kidney disease, also known as nephropathy, sets in when the filtering mechanism of the kidneys is disrupted and proteins escape into the urine in excessive amounts and finally the kidney fails. Therefore there is a medical need for medicaments for preventing and/or treating metabolic disorders (particularly diabetes, predominantly type 2 diabetes) and the complications thereof. In particular there is a need for medicaments with good activity in terms of glycaemic control, disease-modifying properties and reducing cardiovascular morbidity and mortality, and which also have a better safety profile.
Dyslipidemia is a disorder of lipoprotein metabolism, including lipoprotein overproduction or deficiency. Dyslipidemias may be manifested by elevation of the total cholesterol, LDL cholesterol and triglyceride and free fatty acid concentrations, and a decrease in high-density lipoprotein (HDL) cholesterol concentration in the blood. Dyslipidemia occurs often in situations including diabetes, a common cause of lipidemia. For adults with diabetes, it has been recommended that the levels of LDL, HDL, and total cholesterol, and triglyceride be measured every year. Optimal LDL cholesterol levels for adults with diabetes are less than 100 mg/dL (2.60 mmol/L), optimal HDL cholesterol levels are equal to or greater than 40 mg/dL (1.02 mmol/L), and desirable triglyceride levels are less than 150 mg/dL (1.7 mmol/L).
GPR119 is a G-protein coupled receptor (also known as GPCR2, RUP3, SNORF25 or GDIR) which is expressed predominantly in the beta cells of the pancreas and in the K- and L-cells of the intestine. The GPR119 receptor and isoforms have been identified in mammalian species including human, rat, mouse, hamster, chimpanzee, rhesus monkey, cattle and dog. The expression of GPR119 in the pancreas and particularly in the pancreatic β-cells led to the hypothesis that the GPR119 receptor could have effects upon insulin secretion. Activation of the receptor stimulates the cAMP signal pathway, increasing the intracellular levels of cAMP in these cells. This will lead to an improved diabetic situation by a dual action of such a compound: stimulation of cAMP in the beta cell occurs directly via activation of GPR119 in these cells and furthermore indirectly via stimulation of the release of neuroendocrine peptides like GIP and GLP-1 and PYY from the gut. The release of these peptides may have also additional beneficial effects, e.g. on food intake, gastric emptying and other yet unknown functions. Also, a GPR119 agonist can be expected to bring about an improvement in the beta cell function and the beta cell mass. In fact, activation of GPR119 stimulates insulin secretion in-vitro and in-vivo (in rodents) in a glucose-dependent manner. The discovery of two endogenous ligands, lysophosphatidylcholine (LPC) and oleoylethanolamide (OEA) as well as more potent GPR119 agonists have led to the characterization of GPR119 as both an insulin and incretin (GLP-1 and GIP) secretagogue receptor capable of lowering plasma glucose and thereby facilitating glycemic control without the risk of hypoglycemia (Biochem. Biophys. Res. Comm. 2005, 744-751; Cell Metabolism 2006, 167-175; Endocrinolgy 2007, 2601-9). It has recently been shown that GPR119 agonists effectively lower the blood glucose levels in diabetic rodents without the risk of hypoglycaemia. GPR119 knockout animals have shown that both insulin and incretin secretion induced by GPR119 agonists are dependent upon GPR119 receptor. In addition, it has been shown that GPR119 agonists decrease food intake resulting in weight loss in Sprague Dawley rats. Therefore the GPR119 agonists may be expected to have a therapeutic benefit in metabolic diseases. Examples of such diseases include type 1 diabetes, type 2 diabetes, insufficient glucose tolerance, insulin resistance, hyperglycaemia, hyperlipidaemia, hypercholesterolaemia, dyslipidaemia, syndrome X, metabolic syndrome, obesity, high blood pressure, chronic systemic inflammation, retinopathy, neuropathy, nephropathy, atherosclerosis, endothelial dysfunction and bone-related diseases (such as osteoporosis, rheumatoid arthritis or osteoarthritis). For comparison and additional information also see                1. Dhayal, S., Morgan, N. G. The significance of GPR119 agonists as a future treatment for type 2 diabetes. Drug News Perspect. 2010, 23(7), 418-24.        2. Yoshida, S., Tanaka, H., Oshima, H., Yamazaki, T., Yonetoku, Y., Ohishi, T., Matsui, T., Shibasaki, M. AS1907417, a novel GPR119 agonist, as an insulinotropic and β-cell preservative agent for the treatment of type 2 diabetes. Biochem Biophys Res Commun. 2010, 400(4), 745-51.        3. Jones, R. M., Leonard, J. N., Buzard, D. J., Lehman, J. GPR119 agonists for the treatment of type 2 diabetes. Expert Opinion on Therapeutic Patents 2009, Vol. 19, No. 10: 1339-1359.        